1. Field of the Invention
This invention relates to a data transmission system of the type in which a transmitter selectively transmits given data to one or ones of a plurality of receivers connected to one another in a cascade fashion.
2. Prior Art
In a data transmission system in which a transmitter need transmit given data selectively to one or ones of a plurality of receivers, each receiver may be connected to the transmitter by an individual signal transmission cable. However, such a way of connection requires many signal cables and is not economical. Alternatively, the receivers may be connected to one another in series or in a cascade fashion with respect to the transmitter so that the transmitter can serially feed data to all of the receivers. In this case, each receiver is normally provided with a switch module through which its own address or identification code is assigned. And, when the transmitter need transmit given data to a specific one of the receivers, the transmitter outputs the data with an identification code of the specific receiver. The data is then stored in the receiver designated by the identification code. The latter way of connection is useful particularly in a recent electronic musical instrument in which a number of musical tone generating circuits (receivers), each formed as an LSI of an identical construction, are fed with different tone data by a single control circuit (transmitter) to produce different tones simultaneously. In this case, however, it is not desirable to provide each musical tone generating circuit with such a switch module for assigning an identification code, since the increase of switches adversely affects the reliability of the instrument and also makes the circuit and the assembling procedure thereof more complicated.